The human heart contains four valves: a tricuspid valve, a pulmonic valve, a mitral valve and an aortic valve. The main purpose of the valves is to maintain unimpeded forward flow through the heart and into the major blood vessels connected to the heart, for example, the pulmonary artery and the aorta. As a result of a number of disease processes, both acquired and congenital, any one of the four heart valves may malfunction and result in either stenosis (impeded forward flow) and/or backward flow (regurgitation). Either process burdens the heart and may lead to serious problems, for example, heart failure. Various procedures for fixing or replacing defective heart valves are known in the art. In some cases, artificial heart valves can be implanted in the heart of a patient to replace a diseased or damaged heart valve with a prosthetic equivalent.
Prosthetic heart valves can have a variety of designs. Two major types of prosthetic heart valves include mechanical heart valves and bioprosthetic heart valves. Mechanical heart valves can be made of synthetic materials, such as plastics or metals, while bioprosthetic heart valves can be made of biologic tissue mounted on a fabric covered plastic or metal frame. Bioprosthetic heart valves can include animal tissue, such as porcine or bovine tissue, that has been chemically treated to make the valve suitable for implantation in a human. Bioprosthetic valves do not generally require a patient to undergo anticoagulant therapy, which is typically required when using mechanical valves. As such, there is a need to further improve the design of bioprosthetic valves to retain its functionality during the life of the patient and minimize stenosis and regurgitation.